Containers, when partially emptied of their contents, exhibit a wide range of undesirable characteristics. Unless special and often expensive procedures are used, atmosphere enters the container and pollutes it with undesirable elements such as water vapor, air born contaminates, or unwanted oxygen. Containers that are emptied in water baths, space, or in other material baths are damaged or difficult to pour in those environmental elements. The contaminants can pre-maturely cure or damage the product or cause unwanted water condensation, as air sensitive paints and glues harden the skin, fine wines and other preparations oxidize, dry wheat crackers get soggy, or liquid fuel tanks gather water. These are just a few examples. Another undesirable characteristic of a partially emptied container is the tendency for the usable material in the container to loose gas, off gassing to the air space left in the container. Off gassing results in premature curing or damaging of products. It results in loss of material. Materials with water content, when frozen in partially full containers, loose moisture to the air by sublimation and exhibit "freezer burn". Off gassing can cause safety concerns as a mixture of fuel or other flammable vapor and oxygen in a partially full fuel tank can explode. A half full container of a dusty material imposes increased fire hazard if the dust air mixture is combustible, especially if that container is large such as in a storage silo. Containers that are partially filled with toxic or unpleasant material that evaporates emit more or unpleasant odors when opened then full containers do, polluting the environment and creating health risks. Waste disposal and septic system holding tanks under certain conditions emit foul odors. One particularly poignant example of off gassing damage is that which occurs to partially consumed portions of effervescent beverages. Effervescent beverages such as soda, champagne, sparkling wines, coolers, beer and the like, have CO.sup.2 gas dissolved in them, at pressure. Unfortunately the carbonated beverage is stored under pressure in the bottle and after the bottle is opened, the best part of the gas is free is escape the beverage, and the drink goes flat. Even if the cap is replaced, the gas is free to go into the air above the drink, and the bigger that space gets as the drink is "used up", the more gas can escape and the poorer the drink tastes. A second opening of the container compounds the problem and accelerates the damage to the beverage. Leaving a very small amount of beverage at the bottom of the container, will yield in a day, a drink that is almost devoid of effervescence and foremost people, worthless. A problem that the invention deals with as a side benefit is that ice when used to cool a drink, waters down the drink as the ice melts. That is, the water derived as the ice melts contaminates the drink and dilutes it. Management of materials in containers that are only partially full creates a number of management difficulties. For example a characteristic of a partially emptied container is that in many cases, it is more difficult to remove material from it. A half empty tube of toothpaste is harder to squeeze. Rolling up the bottom of a metal squeeze tube can cause the metal to crack if rolling is done improperly. As the mustard or glue in the squeeze bottle is used up, it becomes more difficult to dispense, requiring bottle inverting and shaking. Delicate applications that require the material to be dispensed in a prescribed manner, such as decorative application by artists, precise glue or calk application, and cake icing, become more difficult as the tube or bottle has less usable material in it. Trying to squeeze the usable material in an upward direction, such as encountered when under a car and trying to make the squeeze can of penetrating oil shoot in an upward direction, or putting material from a squeeze bottle onto the underside of a horizontal surface such as a ceiling, is difficult. Containers with simple taps, spigots, petcocks, or fittings must generally have the tap at a low location in the container so that gravity will bring the liquid to the exit opening of the container. Trying to get the last bit out of a squeeze tube is near imposable. Cylinders of expensive gasses can not be completely emptied in easy fashion. When the internal pressure of the gas is equal to the external atmospheric pressure, unless a vacuum is applied, no more gas will come out of the cylinder. Another undesirable characteristic of partially emptied containers is that the contents can move about or splash. In vehicles, this leads to an uneven load that moves about disrupting the smoothness of the ride. Baffles in liquid fuel tanks are currently used to reduce sloshing. In other instances, sloshing causes the material in the container to froth up. For example, a shaken and frothed effervescent beverage sprays all over when opened. Containers in some instances require venting. Air must be let into the container via another opening so that the usable material can exit. The vent often must be manually opened and closed, a labor consuming activity. Air coming in the vent can pollute or damage the usable material in the container. It is difficult to deliver a metered or specific amount of material from a container with out introducing air to the container. A half full container is not as stable as a full container with less weight, can tip over more easily. There is a psychological effect on the user that is different for a full container and a partially emptied one. Taking paint from a can and putting it into other containers for brush dipping or rolling is a messy affair. So is putting the unused portion back into the can. Pumping material requires apparatus of various degrees of complexity. Pumping materials that are environmentally sensitive, in that they are volatile and pollute or in that they are damaged by contact with the atmosphere requires expensive apparatus. Some containers contain usable material and a propellant gas packed under pressure. The compressed propellant gas is used to drive the material out at the push of a button or to spray the usable material. These generally disposable containers loose pressure as the usable material and the gas are used up. In the production and use of containers there are environmental considerations. Because of the problems associated with partially filled containers, products are frequently shipped in smaller containers. While one container is opened and in use, the remaining material is kept fresh in the remaining unopened containers. This technique requires more container wall material per unit of stored usable material because in general, the surface area of the container increases in proportion to the square of of the container's radius, while the volume increases as the cube. Since the surface area of the container is directly related to the amount of material it takes to make the container, in general the greater the number of containers a given amount of usable material is stored in, the more container wall material will be needed to make those containers. Also, more containers generally take more human and machine effort to make. In all, it is more economical as well as more conservative of energy and natural resources to make large containers. The down side is that large containers can lead to increased amounts of spoilage of the unused contents of the containers. Even in small containers, damaged unused material causes loss of energy and natural resources. Utilization of extra energy and natural resources is detrimental to our environment. These losses lead to financial loss. Containers whose contents are packaged under pressure for spray tube delivery, have in the past, used propellant gasses that may be damaging to the environment. In general, it is a difficult problem to remove material from a container without allowing air to contact the remaining portions. It is even more difficult to remove the material under these conditions in metered portions.
Preserving the unused portion of effervescent beverages has also over time proved to be a difficult problem to address economically. Pumps have been developed which will repressurize opened bottles of effervescent material as exemplified by the device disclosed in U.S. Pat. No. 5,322,094 to Janesko. These cumbersome to use as each time the container is opened, the entire container must be repressurized. In addition, CO.sup.2, the gas used for carbonating drinks will transfer, in part, to the air pumped into the container, as the air has too low a partial pressure of CO.sup.2 as it is pumped from the atmosphere into the container. The beverage still goes flat despite all the pumping.
The concept of filling a container with alternate material to keep it full and preserve the contents has been embodied in previous patents. Hohl, U.S. Pat. No. 262,773, patented 1882, shows an apparatus for insertion into a beer keg, the apparatus having a bladder attached that is filled with water from a reservoir mounted above the keg. The reservoir is utilized to fill the bladder with water as beer is removed from the keg via a tap mounted in the keg. A pipe is fitted between the reservoir and the keg. Water flows down a pipe from the reservoir and fills the bladder. A similar device is described by Kish, U.S. Pat. No. 2,762,534, patented 1956. Fluid is forced into a pipe which runs into the keg and into a bladder, that pressure causing beer to flow out another pipe with connection to the inside of the beer keg. Valves are used to regulate that pressure flow. This prior art has not seen wide spread utilization because it is expensive to purchase and extremely cumbersome to use especially in the home environment.